From Gordon Kaswell:
Re: “Other half” of Darwin’s theory passes test (Oct. 13): My first thought is on the general description of evolution as a gradual process wherein mutations slowly spread through a given species, transforming it. It’s the gradualism that bothers me. It seems to be in conflict with the saltational (abrupt shift) pattern observed in the fossil record. Stephen Jay Gould, as I’m sure you know, referred to this saltational pattern as Punctuated Equilibrium. I’m a musician, not a biologist, so it may be that I simply lack the background to resolve the apparent conflict, but I’ve yet to hear of an explanation that makes sense to me. If you can refer me to an article or two, preferably online, that resolve(s) the discrepancy, I’d greatly appreciate it.
My next thought is in regards to the discussion of the trade-offs on attractive characteristics such as a peacock’s tail, vs. such characteristics’ potential detriment in terms of general survival. The whole concept seems to me rather post-hoc. The peacock’s tail provided a good survival “strategy” -- one worth the risk for the peacock, but for the males of other bird species it obviously did not. How do we know this? Because most other male birds don’t have such extravagant plumage. But this isn’t science. It reminds me of the astrologer who says something like “Normally, your Jupiter being in Aquarius would give you such-and-such a trait, but because Mars conjuncts Neptune, the exact opposite happened.” Such post-hoc pronouncements in astrology are utter nonsense, of course. But I fail to see how the Darwinian rhetoric is intrinsically any different.
Finally, I think it’s quite a leap to go from demonstrating the function of simple biochemical atractants produced by single-celled yeasts, to the inference that sexual selection as a driving force in the evolution of complex, warm-blooded, multicellular organisms has been demonstrated.
I would be grateful for any comments from you or your readers.